Then I'd need multiple hard drives for redundancy, and I have to bring them back and read them regularly to make sure the data is all readable. And while I have a large amount of data that I rarely touch, I have a small amount that changes frequently, so I need to include that data in my off-site backup too.

Or I could just sign up for a cloud backup service, spend a month or so uploading my initial snapshot of data, and then backups are automatic and always offsite, replicated, and scrubbed. For $10/month.